Just been to Staples and they're currently offering the Hewlett Packard HPJ5780 multifunction inkjet printer for just £65 (half price). It's an instore only promotion as I couldn't find it online but there were proper posters advertising the deal so I'm pretty sure it's available nationwide. Phone your local store to check though before making a special trip!
This is a good price for a well-known make of multifunction printer that includes a fax.
I bought one last month (£130 in PC World!) and can recommend it. Non-branded cartridges are readily available at a good price from many places. As with most printers, it comes with black and colour cartridges to get you started though.